New Zealand assistant coach Wayne Smith has revealed the All Blacks' newly successful running-rugby style was inspired by the players' desire to play the game the right way.

The All Blacks have visibly emphasised the importance of keeping ball in hand to great effect this season thanks to new law interpretations designed to limit the effectiveness of a kick-and-chase brand of rugby.

But Smith has insisted New Zealand's new style was developed before the rule changes came into effect. Smith says the team decided to press on with an attractive style of play when they played France in Marseille last November for the sake of the game and to help keep players motivated.

Despite a lack of success keeping ball in hand in the 2009 Tri-Nations, the All Blacks swept to a dazzling 39-12 victory over France that day, scoring five tries.

"We were swimming against the tide in last year's Tri-Nations because we were trying to play with the ball in hand, because that's what inspires our players, that's what motivates them, while the kick-chase does not," Smith said after arriving in South Africa for his side's latest Tri-Nations test against the Springboks on Saturday.

"But we were not helped by the laws last year and our skills also let us down. Marseille was the watershed for us because it showed it was possible to use that style of play. It's a great way to play footy and it set us up for this year when the laws did change. We made the assumption that the game couldn't continue the way it was going because it was losing its fan base and it wasn't great to watch.

"We went forward with our vision of how we believed the game should be played and it is what the players wanted to do. It's the best way to get them on edge, so they love what they do, and loving what you do is a big key to success."

The All Blacks play South Africa at FNB Stadium near Soweto on Sunday, needing just one point to clinch the Tri-Nations title, and Smith said he was unsure whether the Springboks would share their enthusiasm for keeping the ball in hand or stick with the kicking game that has helped relegate them to the bottom of the Tri-Nations standings.

"It's a big occasion, there'll be a big crowd, but whether or not there will still be a lot of kicking is all conjecture at the moment. They played more expansively in the second half in Wellington and played some good stuff, so they'll probably throw that at us as well," Smith said.

Although the All Blacks have played some sublime rugby in winning their first four Tri-Nations matches of the current campaign, Smith called for further improvement from the team.

"We still have to go another 25 percent if you take into account the improvement of the other teams, particularly in terms of personnel. Australia and South Africa will be better, so we have no option but to improve. There are areas of our game that we have not got into gear yet, there's still some polishing needed, and there are some areas that we haven't even attempted yet."

One of the areas that has impressed the backline coach has been how the All Blacks have kept their cool in defence. He said: "We're just out of a game against Australia (won 20-10 in Christchurch on August 7) in which they played a lot with ball in hand, they tested us around the fringes and all around the ground. But we were up to it."

Perhaps the All Blacks' only conundrum in terms of the 15 who will take the field at FNB Stadium is whether to play Piri Weepu or the fit-again Jimmy Cowan at scrum-half, and Smith said it all depended on who fitted the bill best this week.

"There is some horses-for-courses involved, but both have been in really good form. Fitness obviously decided the selection for the last game, but they're two players who are really pushing each other. We just need to decide who will give us more starting and who will give us more off the bench this particular week," Smith said. "Selection is more complex than that because they offer slightly different games."